Breast Lumps: Causes and When to Call a Doctor

Medically Reviewed by Sabrina Felson, MD on March 24, 2023
5 min read

You notice that something is different with your breast, and you find a lump. Now what?

If you notice any breast changes, call your doctor right away to get it checked, but don't panic. Most breast lumps are benign, which means they're not cancer. Benign breast lumps usually have smooth edges and can be moved slightly when you push against them. They are often found in both breasts.

There are several common causes, including normal changes in breast tissue, breast cysts or adenomas, injury, or rarely, breast infections.

Breast tissue changes during a woman's entire life. It is sensitive to changing hormone levels during the menstrual cycle.

Fibroadenomas. These are the most common benign lumps. If you push on them, they are solid, round, rubbery lumps that move freely. They’re usually painless. Women between 20 and 30 get them most often. They’re also more common in African-American women. Fibroadenomas can be surgically removed.

Fibrocystic changes. Changes in hormones during your menstrual cycles can create changes in your breasts. These are known as fibrocystic breast changes. You could get lumps in both breasts that increase in size and tenderness just before your period. You might have nipple discharge as well.

The lumps are milk ducts and tissues around them that have grown and widened to form cysts. These  enlarge quickly in response to hormones released near your period. The lumps may be hard or rubbery and could feel like a single (large or small) lump. Fibrocystic changes can also cause breast tissue to thicken.

These changes are often most noticeable during your 40s. They’re the most common cause of benign breast lumps in women ages 35 to 50. Postmenopausal women are less likely to have these types of breast changes. That’s because they don’t have monthly changes in hormones.

They don’t require treatment, but your doctor may recommend ways to ease monthly tenderness.

Simple cysts. Simple cysts are fluid-filled sacs that usually affect both breasts. You could have one or many. They can vary in size. Their tenderness and size often change with your menstrual cycle.

Simple cysts can be treated with fine needle aspiration. This isn’t surgery. Your doctor will place a needle into the area around the lump. If the lump is a cyst, they can suck out the fluid and the cyst will collapse. Cysts can also go away on their own, so your doctor may choose to wait and see if it goes away.

Intraductal papillomas. These are small, wart-like growths in the lining of the mammary duct near the nipple. They usually affect women who are 30 to 50. They can cause bleeding from the nipple. Your doctor can remove them with surgery.

Traumatic fat necrosis. This happens when there is an injury to the breast, though you may not remember an injury happening. It causes fat to form in lumps that are generally round, firm, hard, and painless. You usually get one at a time.

It can be hard to tell if a lump from traumatic fat necrosis is that or something else until your doctor does a biopsy. These usually don’t need to be treated. But if the lump bothers you, the doctor can remove it.

About 20% of the time, breast lumps are cancer.  Still, remember that it's more common for them to be a cyst (a sac) or a fibroadenoma (an abnormal growth that's not cancer). Some lumps come and go during a woman's menstrual cycle.

Yes. Men can have tender breast enlargement, often with a lump under the nipple. Sometimes this is in one breast, but it often happens in both. This noncancerous condition is called gynecomastia.

It can. Sometimes a painful lump, with or without redness, is the first sign of an infection. Mastitis is an infection most common in breastfeeding moms. It happens when bacteria get into the mammary ducts through your nipple. Infection happens in small pockets. You’ll feel tender, warm lumps in your breast.

For relief, try a hot shower and let the warm water flow over your breasts. A warm compress can also help. Sometimes your doctor will prescribe an antibiotic.

See your doctor if you discover any new breast changes, such as:

  • An area that’s clearly different from any other area on either breast
  • A lump or thickened area in or near the breast or underarm that lasts through your menstrual cycle
  • A change in breast size, shape, or contour
  • A mass or lump. It could be as small as a pea or feel like a marble under your skin.
  • A change in how the skin on your breast or nipple looks or feels. It could be dimpled, puckered, scaly, or inflamed.
  • Clear or bloody fluid coming out of the nipple
  • Red skin on your breast or nipple

The doctor will ask questions about your health history. They’ll perform a breast exam to feel for lumps or other changes in the breast tissue and under your arms.

If there’s fluid coming out of your nipple, the doctor may order blood tests to check hormone levels and collect a sample to check for abnormal cells.

They may also do a mammogram or ultrasound to see if the lump is solid or filled with fluid.

Your doctor may order a test called a biopsy. They’ll take a tiny sample of the lump with a needle or small cut and send it to a lab.

Self-examination and mammograms are the most common ways to monitor your breast health. 

Your doctor can help you decide the right time to start and how often to get a mammogram. The American Cancer Society recommends women ages 45 to 54 at average risk for breast cancer get yearly screening. Women 55 and older can switch to getting a mammogram every other year or continue with the yearly screening tests. Women ages 40 to 44 can start a yearly mammogram.

The U.S. Preventive Services Task Force recommends screening mammograms every other year for women ages 50-74. 

If you have a high risk for breast cancer, get a mammogram every year. You may start getting them at a younger age, too. You may also get ultrasound screenings, too. Breast MRI screening tests, in addition to mammograms, is sometimes used in certain women with a high risk of breast cancer. Talk with your doctor to decide what's best for you.